Magnetische Thermoablation mit Ferrofluiden : Einfluss von Gewebeart und Applikationsweg auf den thermischen Effekt
- Magnetic thermoablation with ferrofluids : effect of thermoablation on different ways of application and different tissue
Oversohl, Jessica; Mahnken, Andreas H. (Thesis advisor)
Aachen : Publikationsserver der RWTH Aachen University (2009)
Dissertation / PhD Thesis
Aachen, Techn. Hochsch., Diss., 2009
The main aim of this study was to investigate the effect of magnetic thermoablation on different tissues. The application of superparamagnetic nano particles was explored in two ways: first: as a bolus injection, i.e. the ferro fluids were injected directy into the target. Second: as a permanent infusion with the aid of a perfusor, so that the nano particles were injected continously during the period of ablation. Three different ferro fluids containing different concentration of ferro oxide particles (171 mg/ml, 192 mg/ml, 214 mg/ml) were tested three different tissues each (kidney, liver, muscle) of a pig. The samples were exposed to a varying magnetic field caused by circular coils for 5 minutes. Two optic temperature probes were used to detect the temperatures in the centre and the circumference of the nano particle depot. They were implanted in a distance of one centimeter to each other. The temperatures were measured until reaching the output temperature. Then the tissues were were checked on any signs of necrosis, like brightening tissue around black nano particles. With the bolus application the following average maximum volume of necrosis was found out: the maximum volume of necrosis in kidney tissue (149, 33 ± 59,37 mm³) was reached with fluid 3 (214 ng/ml), in the liver tissue the maximum (199,91 ± 77,65 mm³) was also reached with fluid 3 (214 ng/ml), and again the maximum in the muscle tissue ( 199,18 ± 123,66 mm³) with fluid 3 (214 ng/ml). With the permanent infusion higher average maximum volumes of necrosis were reached: the maximum volume of necrosis in kidney tisuue was 976,41 ± 565,52 mm³ , reached with fluid 2 (192 ng/ml), in the liver tissue the measuring showed a maximum volume of necrosis of 457,21 ± 242,96 mm³, also reached with fluid 2 (192 ng/ml). The result for the muscle tissue was 1441,47 ± 438,19 mm³ reached with fluid 3 (214 ng/ml).he highest temparatures with the bolus injection were reached in kidney with 64 ± 6,09°C, in liver 75,94 ± 9,34°C, and in muscle 64,32 ± 7,61°C. With the permanent infusion the results wre as lollows: a maximum temperature of 78,44 ± 4,27°C in kidney, 73,82 ± 9,55°C in liver and 69,22 ± 3,40°C in muscle. The results of this study verify the feasibility of magnetic thermoablation in different applications, i.e. the bolus injection and the permanent infusion. The permanent infusion reached larger zones of necrosis in comparison to the boplus injection. In addition to that the results show that there are significant differences between the three tissues (kidney, liver, muscle) in the maximum temperatures and the size of necrosis. Thermoablation with the help of nano particles is a chance of reaching and treating neoplasm in alomost any area of the human body, without any radiation exposure of the patient, with hardly any danger of unwanted secondary facts.